Process for manufacturing pure, white and finely distributed sulphate of barium and sulphate of calcium



145 verted into combinations, which Patented Sept. 8, 1931 UNITED STATES THEODQR LICHTENBERGER AN D Ll' J'IDWIG KAISER, on HEILBRoNnpn THE-NEoKAn,

GERMANY PROCESS FOR MANUFACTURING PURE, WHITE AND rrnnny nrsrn nu'rnn or BARIUM AND SULPHA'IE OF cALoIuM no Drawin Application filed March 22', 1927,

The subject of the present invention is a calcium.

raw materlals, heavy spar, gypsum or anhydrite are dissolved in molten salts which,

as chlorides of alkali metal, are fusiblewithout decomposition and wh ch 1n their molten 1 state do not exert any decomposing ehect upon sulphate of barium and sulphate of calcium, whereupon the insoluble substances are separated from the solution by settling and the molten mass is freed from the dis solved impurities by blowing air into said molten mass; the mass is clarified agam and the purified sulphate is recovered by extracting the soluble salts by use of water.

The advantage of the process conslsts 1n producing a pure, white product of a chemically high grade and in avoiding thereby the expensive and tedious way over the sulphides of and chlorides of barium and calcium.

' The process can for instance be earned out in the following manner:

15, parts sulphate ofbarium and 20 parts.

of sodium chloride are mixedran'd h'eated,. themelting-point of thismixture not being beyond that of pure chloride'of sodium.

Both crude materials are preferably employed in coarse lumps,'thereby not only the-- very considerable costof grinding is avoided, but likewlse the very onerous dust...

As soon, as a thin liquid molten mass has been produced, the insoluble substances are separated by settlingandthe molten mass is drawn off to a second hearth on which asmall;

quantity of oxide of calcium is added and air is blown into the molten mass.

calcium and air, being either burned, or con uble in the molten mass;

If these impurities are allowed to'settle,

According to the present invention the The molten mass thereby becomes freed from the oxidizable part and such impurif Whlch can be decomposed by Oxide 'lralimetal,separating thelinsolu'ble substances l are insole It is granuw; lated in water, or cooled rapidly in some; 2.-.Aproeess for'manufaoturingpure,'rwhite Serial 30. 177,472, and in Germany April 3, .1926.

other way and afterwards. treated. with process for producing pure, White and finely divided sulphate ofbarium' and sulphate of water. i

I A pure White and finely divided sulphate of. barium remains as a residue fronr the molten mass. This white sulphate of barium is inno way inferior to the blanc fixe' precipitated: from a solution of chloride of barium bysulphuric-acid. Small quantities of sulphate of calcium contained in the molten mass are dissolved by the chloride of sodium. It is therefore possibleto produce a high grade product directly: from the crude materials, without the necessity of producing previously sulphide ofbarium and chloride of barium. Instead of chlorides of alkali metal, other salts or mixtures of different salts maybe employed, as long as they .or-the mixtures of salts can be melted without decomposition and exert no decomposing effect in molten Instea'd of oxide of calcium other additi o nal substancesmay be "used for instance s1l1c1c acid.

consisting of chloride oflalkalimetaland cal- 'SULPHATE It is'not necessary the preliminary PHIlfiCELiElOII ofthemolten mass. of chloride and barium, sulphate or of themolten mass cium sulphate is effected separately by settling 1 and. further treatment of the molten.massby air with or Without the: addition ofbasic or acid substances but particularly in the case of:

purer .crude materials, both processes-may becarried outsimultaneously in one hearth. We claim: l V

. 1. A process for manufacturing pure, white and finely divided sulphate of barium and sulphate of calcium consistingin dissolving the raw sulphates in molten chlorides of al- .from the-solution by settling, freeing the Y iblowingair into.said-moltenmass, clarifying again--and solidifyingsaid mass andrecovering-thepur ified sulphate by extractingthe soluble'chloridesof alkalimetal with water.

molten massfrom the dissolved impurities by" fying again and solidifyingsaid mass and rea covering the purified sulphate "by extracting the soluble chlorides of alkali-earth metal with water.

3. A process for manufacturing pure, white sulphate of calcium consisting in dissolving the raw sulphates in molten mixtures of chlo- Irideslof alkalimetal and chlorides of alkalithe molten mass'froin the dissolvedinipuri- .tiessby blowing air into the molten mass, clarifying again and solidifying said mass and recovering the purified sulphate by extracting the soluble mixtures of chloridesofalkali metal and chlorides of alkali-earth metal with water.

:4. A. process for manufacturing pure, white and finely divided sulphate of barium and ,jsulpliate of calcium consisting in dissolving the raw sulphates'in molten mixturesof chlorides of alkali-earth-metal and'sulphates of alkali metal separating the insoluble substances from the solution bysettling, freeing the molten mass from the dissolved impurities :by'lolowing air into:tlie molten mass, clarivfying again and solidifying said mass and recovering'the purified sulphate {by extracting the soluble mixtures of chlorides "of alkaliearth metal andsulph-ates of alkali metal with water. V

' 5.. Aprocess'for,manufacturing piire,white -:=and finely divided sulphate iof barium and sulphate of calcium consisting inldissolving zthe sulphates in molten chlorides of alday vblowing air into said molten mass and ElCllClIIlgOXIdQ of calcium, clarifying again and solidifying said-mass and recovering the, purified sulphate by extracting the soluble chlorides of alkali metal with water. v

(i. .A processfor manufacturing pure, white I and finely divided sulphate ofibariuni and sulphate offcalcium consisting in dissolving the raw sulphates in molten chlorides of aldiali-earth metal separating the insoluble sub; V stances from the solution by settling, freeing themolten mass from the dissolved inipuri .tiesby blowing .airinto said molten mass and -adding oxide of calcium, clarifyingagain' and solidifying sa dmass'and recovering the signatures.

ingthe molt-enmasstnom the dissolved impurities by blowing air into said molten mass and adding oxide of calcium, clarifying again and solidifying said mass and recovering the purified sulphate by extracting the soluble mixtures of chlorides'vof alkali metal and chlorides of1alkaliearth metal with water. and finely divided sulphate 'ofbariu'ms and 8. A process for manufacturing pure, white and finely, d vided sulphate of barium and sulphate of calcium consisting in dis solving the raw sulphates inmoltenchlorides earth metal, separating the insoluble sub stances from the solution bysett'ling, freeing A eta-alkali metal separating the insoluble substances :from the solution by settling, jf-reeing the molten mass from the dissolvedimpurified sulphate by, extracting the employed chlorides of alkali metal with water.

9.. A process ,for manufa-cturing pure, white and finely divided sulphate of barium and sulphate of calcium consisting in :dissolving the raw .sulphatesin molten chlorides of alkali-earth metal separating the insoluble substances from the solution-by settling, vfreeing the molten mass fronithedissolved inip iritiesby blowing air into said molten mass, clarifying again and graniilating .said inassby; pas-si it into water and recovering the purified sulphate by extracting thee u ployed chlorides falkali earth metal with water. q

1O A process for manufacturing pure, white andfinelyi divided sulphate of barium and sulphate of calcium consisting in dis solving the rawsulphates in molten mixtures of chlorides ofalkali metaland chlorides of ;alkai-earthmetal separating the insoluble chlorides of alkali-earth m'et.al with Water.

In testimony whereof we have'a'l'fixed our TI-IEODOR l 'f iioiirnnnnnena. DafLUDWIG KAI-sun,"

purified sulphate by extracting the soluble chlorides of alkali-earth metal'with water? V. 7. Aprocess for manufacturing pure,-white andxfinely -dix' ided -s'ulphate of helium and i 

